This invention relates generally to methods and apparatus for providing precisely measured amounts of granular materials and, optionally, precisely measured amounts of coloring agent(s), particularly pigment in liquid form, preparatory to further processing of the combined granular materials and, optionally, liquid coloring agent(s), and specifically to weigh scale blenders, optionally in combination with color addition pumps, providing precisely measured amounts of plastic resin material, and, optionally liquid coloring agents, and mixing these components prior to supplying the blended mixture to plastics manufacturing and processing equipment such as plastic injection molding, compression molding and extrusion equipment.